One of the most medically useful agents for general germicidal, fungicidal and even viricidal application over the ages has been elemental iodine. In addition to its microbiocidal property however iodine has a second complexing property which over recent years has caused it to be complexed with a water soluble polymeric polyvinyl pyrrolidone as disclosed in Shelansky U.S. Pat. No. 2,739,922 issued in 1956. Over the past 20 years this composition of P.V.P (polyvinyl pyrrolidone) and iodine has established itself as the product of choice in bactericidal applications especially in surgery and medicine. It is used to coat the skin in preparation for surgery and as a topical ointment for wounds and burns to keep down bacterial infections.
However, Shelansky's P.V.P.-iodine complex has certain chemical and physical limitations which serve to limit its fields of application. One problem is that the use of a P.V.P.-iodine complex on a dressing or tape is not practical because the P.V.P. being water soluble in the complex can be pulled off a substrate unless it is packaged in a water proof container. A second proplem is that the time limit on the iodine microble killing power is established by the relative acidity of the wound or skin or rather the loss of the same by the generation of alkaline materials. LeVeen patent application Ser. No. 665,915 recently filed has addressed itself to the solution of the latter problem by adding to the P.V.P.-iodine complex a high molecular weight acid such as polyacrylic acid. This retards the conversion of elemental iodine to an inactive iodide salt which occurs in a basic medium. The former problem is not capable of solution so long as the pyrrolidone component of the complex is P.V.P. which is totally water soluble and thus readily gives up its bound iodine in the presence of water. A new pyrrolidone complexing agent for the reactivated elemental iodine must be found which is not water soluble yet is sufficiently reactive to iodine so that it takes the same up quickly and gives it up slowly under the preservative effect of the polymeric acid on the iodine.